Cardiac electrical signal morphology and pattern-based t-wave oversensing rejection

A method, comprising:

• sensing a cardiac electrical signal;
• determining a morphology match score for each of a plurality of time segments of the sensed cardiac electrical signal;
• comparing each of the morphology match scores to a first R-wave match score threshold;
• comparing at least a first portion of the morphology match scores to a second R-wave match score threshold, the second R-wave match score threshold less than the first R-wave match score threshold;
• determining that the first portion of the morphology match scores are greater than the second R-wave match score threshold;
• and
• detecting T-wave oversensing at least in response to the first portion of the morphology match scores being greater than the second R-wave match score threshold.

A non-transitory, computer-readable storage medium comprising a set of instructions which, when executed by a control circuit of a medical device, cause the device to:

• sense a cardiac electrical signal;
• determine a morphology match score for each of a plurality of time segments of the sensed cardiac electrical signal;
• compare each of the morphology match scores to a first R-wave match score threshold;
• compare at least a first portion of the morphology match scores to a second R-wave match score threshold, the second R-wave match score threshold less than the first R-wave match score threshold;
• determine that the first portion of the morphology match scores are greater than the second R-wave match score threshold;
• and
• detect T-wave oversensing at least in response to the first portion of the morphology match scores being greater than the second R-wave match score threshold.